Every single Yahoo customer could be caught up in a data breach, the company has admitted.

The technology giant said one billion accounts worldwide, including the North East, have been compromised in a hacking incident which took place in 2013.

Here we answer your questions about what happened and what to do now.

Yahoo? Do people still use Yahoo these days?

Yes, they do, you will be surprised at how many people still have a Yahoo account. It was one of the first companies to jump on the bandwagon when the internet came along and, although it has lost ground since, it’s still a big deal.

Yahoo is subject to a takeover bid worth $4.8 billion so its value is not to be sniffed at although it is a minnow compared to Facebook and Twitter.

What was nicked?

Personal information including names, email addresses and security questions were all accessed by a mysterious hacker.

The stolen info will include telephone numbers, dates of birth, hashed passwords and security questions and answers.

But Yahoo claim no financial information has gone missing because it was not stored on the affected system.

Read More

How did they do it?

It will be a puzzle to most of us but experts think they got in by forging cookies - data stored on computers which record which websites were visited.

The forged cookies allowed hackers to get in without the use of passwords.

Who did it?

Conspiracy theories suggest it was a state-sponsored hacking. Look to Russia or North Korea as possible suspects.

But how about a bored teenager in his bedroom?

Kids often break into what are supposed to be sophisticated security systems.

What kind of accounts are most by risk?

The company has a range of services, including email, Tumblr, Flickr and Yahoo Finance, all of which are believed to be at risk.

Yahoo believe hackers stole personal data from more than one billion user accounts as part of a cyber attack that occurred in 2013 (Image: PA)

What do Yahoo suggest I do if I think I am affected?

All Yahoo users are being encouraged to change their passwords and security questions, and to also do so “for any other accounts on which you used the same or similar information used for your Yahoo account”.

“We are notifying potentially affected users and have taken steps to secure their accounts, including requiring users to change their passwords,” Yahoo said.

“We have also invalidated unencrypted security questions and answers so that they cannot be used to access an account.”

What else is a sensible precaution?

Users should avoid clicking links or downloading attachments from suspicious emails and be cautious of unsolicited communications that ask for personal information.

Try not to have the same passwords for everything and avoid anything that might identity you, such as a favourite band or child’s name.

Change it regularly. Include numbers as well as letters and, if you’ve a good memory, chose something random.

Experts suggest staying about from public wi-fi and, if you can’t, not to share financial or personal information.

Read More

Anything else.

Citizens’ Advice say: “Only allow someone to remotely access your computer if they are from a trusted source, such as your internet service provider.

“No genuine online company will contact you to ask for your log-in details, such as your password or user id. You should only need to provide this information when you are logging onto a service such as online banking.”

How will it affect Yahoo?

Expect the takeover offer to come down.

There will also be the embarrassment factor to take into consideration and some customers will take the opportunity to jump ship.

This was the second Yahoo hack following one which was reported in September and it’s reputation for security will be badly affected.